Spring base for seat backs



March 16, 1965 R. o. xsAAcs 3,173,672

SPRING BASE FOR SEAT BACKS Filed Jan. 22, 1962 INVENTOR. abfrz d $2265 United States Patent O 3,173,672 SPRING BASE FOR SEAT BACKS Robert 0. Isaacs, Joplin, Mo., assigner to Flex-O-Lators, Inc., Carthage, Mo., a corporation of Missouri Filed Jan. 22, 1962, Ser. No. 167,703 3 Claims. (Cl. 267-162) This invention relates to new and useful improvements in upholstered, spring-biased furniture, and has particular reference to a spring base particularly suitable for use in seat backs.

Among the principal objects of the present invention is the provision of a spring base which is quite hrm and capable of holding its form through long periods of hard usage, so as to preserve the padding and upholstery layers applied thereover in a neat, tailored appearance, and which at the same time possesses a degree of softness and yieldabilityquite adequate for comfort. The upper edge of base is resiliently yieldable, for greater comfort, and yet is sufficiently irm and well supported to prevent sagging or the assumption or" an uneven, undulating line even after long periods of usage. Provision is also made for preventing lateral movement or side sway of the upper edge of the base structure. The base structure involves spring strips more or less rigidly fixed at their upper and lower ends, and having their intermidiate portions bowed forwardly. This type of structure, which is quite common in seat backs, has a common fault in that as said strips are deflected rearwardly by a persons back to a rearwardly bowed position, they tend to snap, or change their direction of bowing very suddenly as they pass between their upper and lower supports. This causes a disconcerting, uncomfortable sensation. The present structure has novel means for overcoming this fault.

Another object is the provision of a spring base of the character described which is adapted to be supplied to furniture manufacturers as a completely integrated unit not requiring any additional assembly, and which may be mounted in a furniture frame with the least possible time and labor, and with no tools or implements other than hammer and nails. Before mounting in the furniture frame, the base may be collapsed into a compact, convenient form for greater economy of storage, handling and shipping.

Other objects are economy and simplicity of structure, efficiency and dependability of operation, and adaptability for use in furniture of a wide variety of styles and types.

With these objects in view, as well as other objects which will appear in the course of the specification, reference will be had to the drawing, wherein:

FIG. l is a iront elevational view of the back portion of a furniture seating frame, showing a spring base embodying the present invention mounted therein, with the padding and upholstery layers omitted,

FIG. 2 is a sectional view taken on line ll-ll of FIG. 1, and

FIG. 3 is a view of the spring base only, separated from the furniture frame and collapsed for shipment or storage. o

Like reference numerals apply to similar parts throughout the several Views, and the numeral 2 applies generally to the back frame of a furniture piece such as an upholstered chair, couch, sofa or the like, the remainder of the frame not being pertinent to the present invention and not being shown here. Said back frame comprises a pair of side uprights d connected at their upper rear portions by a horizontal cross bar 6, at their lower rear portions by a cross bar 8, and at their lower forward portions by a cross bar 1li. Said uprights and cross bars are formed of wood or other suitable material, and are rigidly connected to form a rigid frame. In the particular ICC embodiment illustrated, the upper portions of uprights 4 are offset outwardly to form wings 12 which is the nished chair will overlap the upper surface of the chair arms.

The spring base forming the subject matter of the present invention is indicated generally by the numeral 14, and includes a plurality of compound spring units (four illustrated) each indicated generally by the numeral 16. Each of said units comprises an upright spring steel strip 18 arranged to flex forwardly and rearwardly and lixed at its lower end to frame cross bar 10 as by a nail 20, and a generally S-shaped support spring strip 22 (see FIG. 2) aiiixed at one end to strip 1S in adjacent but spaced apart relation from the upper end thereof, as by a pair of rivets 24. From its point of attachment to strip d8, support strip- 22 is curved rearwardly and downwardly, then rearwardly and upwardly, and is aliixed at its opposite end to trarne cross bar 6, as by nail 2o. The upper end portion of upright strip 18 is thus normally supported well forwardly of cross bar 6, and said upright strip is flexed in a forwardly bowed position as shown in FIG. 2. rl`he spirng units lo are disposed generally in regularly spaced relation across the width of the chair, as indicated in FIG. l. A greater or smaller number of units could be used, as desired or necessary.

The upper ends of all of upright strips 1S are joined by a horizontal cross spring strip 28, said cross strip being connected to each strip .18 at its point of intersection therewith by a rivet 3G, said rivet being suiciently loose to permit relative pivoting of the parts when not otherwise restrained. Similarly, strips 18 are joined adjacent their lower ends by a horizontal cross spring strip 32 connected thereto by loose rivets 34. The upper cross strip 2S is extended at its ends laterally outwardly from the associated strips 1S, and has a hole 36 formed in each extended end portion thereof. One end of a tension spring 38 is secured in each of holes 3o. Said springs extend laterally outwardly and rearwardly, and are secured at their opposite ends to nails 40 driven in the upper ends of frame uprights 4. Intermediate cross strip 28 and the point of its attachment to support strip ZZ, each upright strip 1S has a rearwardly oiset bight d2 formed therein, for a purpose which will presently be described. It will be understood that the frame 2 andspring base .1li is in actual use covered by layers of upholstery material such as spring insulation, padding and decorative fabric, but that these layers have been omitted from the drawing for purposes of clarity.

ln use, it will be seen that as a person leans rearwardly against .the back, the upright strips 18 will be exed to a rearwardly bowed position, and also dellected rearwardly against the yielding resistance of S-shaped support strips 22. Moreover, as strips 18 move from a forwardly to a rearwardly flexed position, the upper ends thereof must move upwardly to some degree. Support strips 22 will yield vertically as well as horizontally to permit this lengthening of strips 18. However, since upright strips 18 are seldom flexed equally, but usually A unequally depending on where the persons weight is applied to the back, the vertical movement of their upper ends is also unequal. Therefore, if their upper ends were only loosely connected rather than by spring cross strip 2S, permanent yielding and deformation of the springs would soon cause the upper edge of lthe spring base to assume `an uneven, vertically undulating shape, and the overlying upholstery layers would sag and become unsightly. Cross strip 28 largely solves this problem. While it may be freely flexed forwardly and rearwardly, and thus does not interfere with normal yieldability of the spring base, it possesses comparatively great resistance to flexing in a vertical plane, and thus resists theV previously described unequal vertical movement of the upper end of strips 18 as they are flexed. The upper edge of the spring base, and hence of the :overlying upholstery, is thus maintained straight and neat even after long periods of hard usage.

However, if it were not for the use of lbights 42, the use of cross strip 28 would introduce another problem. It will be seen that if one or two of strips 18 were iiexed rearwardly, but not the others, upward `movement of the exed strips would be resisted, by cross strip 28, and uprigh-t strips 18 would be forced to move between bar 1t) and cross strip 28, and to reverse their direction of bowing, when the space between bar 16 and strip'28 is less than the total length of upright strips 18. Thus strips 18, as` they are forced rearwardly between bar and strip 28, would be forced into a sort of S-shaped exure, and would then snap into a rearwardly bowed position. This snapping action is uncomfortable and disconcerting, and is considered to be quite objectionable. Bight 42 in each upright strip 1S solves this diiiculty in that as the strip is forced rearwardly, the bight contracts and shortens the strip so that it can pass between bar 1t! and cross strip 28 in a substantially linear or straight position, whereby it can move from a forwardly -to a rearwardly bowed position with a smooth, stepless motion. In other words, bights 42 permit each strip 18 to function or ex independently of each other, although they are tied to each other at their upper ends by strip 28. Springs 38 serve to resist yieldably any side or lateral movement of the upper end of the spring base, which otherwise would create discomfort. frame were not provided with wings 12, springs 38 could be attached to strip 28 at points nearer the center thereof. The lower portion o f the spring base of course cannot move laterally, since strips 18 are connected directly to frame bar 10. Since bar 10 is disposed several inches below the level of the seat cushion surface of the chair (not shown), said bar cannot cause discomfort to the occupant of the chair.

Before Vthe spring base is mounted in the frame 2, it

l will be seen that cross strips 28 and 32 form a series of parallelograms with upright strips 18, and that by virtue o f the pivotal connections provided by rivets 30 and 34 the spring base may be'collapsed as shown in FIG. 4, so that spring units 16 lie in directly adjacent planes. This greatly reduces the bulk of the spring base, and constitutes a great advantage when storing, shipping or handling said bases, in that a much greater number of them may be packed into a small space. Assembled spring decks or bases of the general type shown are notoriously inconvenient and expensive to ship and store, due to their extremely large space requirements in proportion to their weight. This expense has made it necessary in many instances to sell and ship the spring bases in a knocked-down or disassembled condition, so that assembly and mounting thereof was a tedious and expensive procedure for the furniture manufacturer utilizing them. The present base may feasibly be furnished in completely assembled form, and may be mounted with only hammer and nails.

While I have shown and described a specific embodiment of my invention, it will be readily apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention as defined by the scope of the appended claims.

What I claim as new and desire to protect by Letters Patent is:

1. In combination: (a)v a furniture back frame including rigidly associated top and bottom horizontally cross bars, and (b) a spring base mounted in said frame and com prising:

(1) a plurality of upright spring strips spaced If the backV regularly across said frame and each affixed at its lower end to said bottom cross bar and extending upwardly therefrom, .the intermediate portion of each strip being normally bowed forwardly and the upper end thereof being spaced apart forwardly from said top cross bar, each of said upright strips having a rearwardly offset bight formed therein intermediate its ends,

(2) a .compressible support 'spring element se-4 cured at its forward end to each of said strips' in spaced relation from the upper end thereof, and secured at its rearward end to said top cross bar, and

(3) a horizontal cross strip extending across said spring base and secured to the upper endsof all of said VVupright strips, said cross strip being of flattened cross-sectional contour with its major cross-sectional axis disposed vertically,- whereby to permit easy exure thereof for= wardly and rearwardly, but to be highly resistant to flexure in a vertical plane.

2. The combination as recited in claim l wherein the bight in each'of said upright strips is disposed intermedifV ate said cross strip and the point of attachment of said support spring theretoi (a) a furniture back frame including rigidly associated top and bottom horizontal cross bars, and

(b) a spring base mounted in said frame and corri;

prisin'g:

(l) a plurality of upright spring strips spaced apart regularly across said frame and each af= fixed at its lower end to said bottom cross bar and extending upwardly therefrom, the intere mediate portion of each strip being normally bowed forwardly and the upper end thereof being spaced apart forwardly from said top cross bar,

(2) a compressible support spring element ser cured at its forward end to each of said strips' in spaced relation from the upper end thereof,- and secured at its rearward end to said top cross bar,

(3) a horizontal cross strip extending across said spring base and secured to the upper end of each of said upright strips for pivotal move' ment vabout an axis at right angles to said upd right and cross strips, and

(4) a second cross strip parallel to said rst dross? strip and connecting said upright strips adjacent' their lower ends and being pivoted to each up right strip on an axis parallel to the pivotal con-j nections of said first cross strip, each of said upright strips and the support spring associated therewith constituting 1a planar unit, said units being disposed in parallel planes, whereby when said spring base is detached from said frame it may be collapsed so that said units lie in parallel abutting relation, by reason of the pivotal connection of said rst and second cross strips thereto. f

References Cited by the Examiner UNITED STATES PATENTS 1,737,112 11/29 Doty 267-104 X 2,029,182 1/36 Meutsch 267-102; 2,284,108 5/42 Thomas 267-102; 2,480,667 8/49 Neely 267-107' FOREIGN PATENTS 271,639 6/27 Great Britain.

ARTHUR L. LA POINT, Primary Examinen. 

1. IN COMBINATION: (A) A FURNITURE BACK FRAME INCLUDING RIGIDLY ASSOCIATED TOP AND BOTTOM HORIZONTALLY CROSS BARS, AND (B) A SPRING BASE MOUNTED IN SAID FRAME COMPRISING: (1) A PLURALITY OF UPRIGHT SPRING STRIPS SPACED REGULARLY ACROSS SAID FRAME AND EACH AFFIXED AT ITS LOWER END TO SAID BOTTOM CROSS BAR AND EXTENDING UPWARDLY THEREFROM, THE INTERMEDIATE PORTION OF EACH STRIP BEING NORMALLY BOWED FORWARDLY AND THE UPPER END THEREOF BEING SPACED APART FORWARDLY FROM SAID TOP CROSS BAR, EACH OF SAID UPRIGHT STRIPS HAVING A REARWARDLY OFFSET BIGHT FORMED THEREIN INTERMEDIATE ITS ENDS, (2) A COMPRESSIBLE SUPPORT SPRING ELEMENT SECURED AT ITS FORWARD END TO EACH OF SAID STRIPS IN SPACED RELATION FROM THE UPPER END THEREOF, AND SECURED AT ITS REARWARD END TO SAID TOP CROSS BAR, AND (3) A HORIZONTAL CROSS STRIP EXTENDING ACROSS SAID SPRING BASE AND SECURED TO THE UPPER ENDS OF ALL OF SAID UPRIGHT STRIPS, SAID CROSS STRIP BEING OF FLATTENED CROSS-SECTIONAL CONTOUR WITH ITS MAJOR CROSS-SECTIONAL AXIS DISPOSED VERTICALLY, WHEREBY TO PERMIT EASY FLEXURE THEREOF FORWARDLY AND REARWARDLY, BUT TO BE HIGHLY RESISTANT TO FLEXURE IN A VERTICAL PLANE. 